Multiuser Gaussianity and Constellation Randomization for the MIMO Multiple Access Channel: A Unified View
2007 (English)In: Proceedings of the 8th IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC'07), IEEE Press, 2007Conference paper (Refereed)
In recent analyses of multiuser MIMO systems and their capacity achieving transmit strategies, Gaussian codebooks are usually used. For the case in which the input signals are constrained to belong to a finite constellation, we study and explain two effects, namely multiuser Gaussianity (MuG) and constellation randomization (CoRa). MuG means that the more users transmit simultaneously, the higher is the similarity of the received density to the optimal Gaussian one. Hence, the instantaneous mutual information is increased by MuG. This leads to a tradeoff between multiuser diversity and MuG. On the other hand, CoRa is done by linear precoding by random unitary matrices. Based on the observations from MuG, we explain why the outage capacity is increased by CoRa. The effects are illustrated by various numerical simulations.
Place, publisher, year, edition, pages
IEEE Press, 2007.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-42499DOI: 10.1109/SPAWC.2007.4401298ISI: 000255431000026Local ID: 65141ISBN: 978-1-4244-0954-9ISBN: 978-1-4244-0955-6OAI: oai:DiVA.org:liu-42499DiVA: diva2:263356
IEEE 8th Workshop on Signal Processing Advances in Wireless Communications, 2007. SPAWC 2007.